Shearing method

ABSTRACT

A method of shearing a stated quantity of each of a number of different sized parts from sheet stock wherein the orientation of stock feed alternates in a predetermined pattern, and wherein the parts to be produced are laid out on the stock so that the first two cuts yield a parts blank and at least one cutoff. The parts blank is then sheared into parts, and the cutoff is sheared in two cuts into a second parts blank and the sequence repeated until the starting sheet is consumed.

United States Patent [72] Inventors Ronald S. Williams 3,490,147 1/1970Brichard et a1. 83/39 X Lexington, Ky.; 3,490,320 1/1970 VaIembois etal. 83/39 John J. Erhart, Cincinnati, Ohio 3,503,290 3/1970 Valembols etal. 83/23 [21] Appl No. 713,088 2,788,069 4/1957 Noojin,.1r. et a1.83/50 X [22] Filed Mar. 14,1968 3,129.622 4/1964 Pearce 83/36 [45]Patented Aug. 10, 19 Primary Examiner-Frank T. YOSl [73] Ass'gnee TheAttorney-Melville, Strasser, Foster & Hoffman Cincinnati, Ohio [54]SHEARING METHOD 8 Claims, 5 Drawing Figs.

[52] US. Cl 83/36, ABSTRACT; A method f shearing a Stated quantity feach 83/42 of a number of different sized parts from sheet stock wherein[51] lnt.Cl 826d 3/00 the orientation f Stock feed alternates in apredetermined [50] Field of Search 83/36, 35, pattern, and wherein thepans to be produced are laid out on 23; the stock so that the first twocuts yield a parts blank and at least one cutoff. The parts blank isthen sheared into parts, [561 Rein-mm cued and the cutoff is sheared intwo cuts into a second parts blank UNITED STATES PATENTS and thesequence repeated until the starting sheet is con- 3,242,573 3/1966 Noel33/1 sumed.

BULK INTERPOLATE 1 DATA & SEOUEN E COMMAND INPUT SCANN/N I CON7'ROL 10078 T r NEW 76 RETURN OPERATOR DATA 1" sc/eAP COMMAND COMMAND EONTROLDISPLAY 1 t I t t t 86 PROGRAM 0 BACK SOUARING BACK FRONT H V ADVANCE 55?? EPROBE PROBE GAGE GAGE 98/ CONTROL EONTROL CONTROL CONTROL CONTROLENCODER 88 1 ENCODER COMPARATOR 90 @MPARATOR Patented Aug. 10, 19713,598,007

2 Sheets-Sheet 2 SHEET LENGTH PART LENGTH SHEET WIDTH QUANITY PARTWIDTHGAGE LENGTH GAGE WIDTH FRONT GAGE I i. A6 I A A @g 1 E J 4-Z{ 62 41: 5-Z BULK INTERPOLATE DATA DSEOUENCE COMMAND /NPUT SCANNING CONTROL 5 I 278 NEW 76'- RETURN OPERATOR DATA "SCRAP COMMAND COMMAND CONT/20L DISPLAY86 I W J, J a t a PROGRAM SHEAR BACK SQUARING BACK F/ZONT ADVANCECONTROL PROBE PROBE GAGE GAGE CONTROL CONTROL CONTROL CONTROL CONTROLTtT 92 34 30 -c00/2 F 88 82 & ENCODER 2 g z ONALD ILL/AMSQ' 4 aCOMPARATOR JOHNJ ERHART,

SHEARING METHOD BACKGROUND OF THE INVENTION This invention relates to anoperation wherein number of different sized parts (each having aspecific quantity requirement) are to be cut from the same gauge andtype of material. According to the prior art, the operator of a shear isgiven a list of parts to be produced, and then he simply manually setsup the machine and begins cutting parts to meet the require mentsspecified. When a sufficient number ofa particular part have beenproduced, the operator will usually have a piece or pieces of materialleft over. This piece or pieces must either be discarded as scrap, orretained and stored as stock for use in cutting subsequent parts. Suchstorage creates inventory problems, and the man hours lost in storingthe odd size piece and later retrieving it reduces efficiency.

This problem is more complicated when, for example, the operator has inhis possession only a list of parts to be produced that day or thatweek. By quickly scanning that chart, he may decide that the left overpiece or pieces of stock will not be of use during the immediatelyforeseeable time period, and then he must balance the economics ofhaving to store this piece or pieces for a period of time as comparedwith the loss realized in simply discarding it as scrap.

In addition, the operator may have sheared the large stock sheet in amethod that does not produce the cutoff with the most usable dimensions.This of course amplifies the scrap storage problem.

Accordingly, it is widely recognized in industry that a shearingoperation of this type involves a rather substantial scrap percentage.In addition, and as compared with other industrial processes, the volumeoutput is generally low because of the setup time required duringoperation.

The instant invention has for its primary object the development of ashearing method which will minimize the scrap percentage for theoperation during any given periodof time.

A further object of the invention is the provision ofa shearing methodwhich will permit automatic setting of the gauges in order to minimizeset up time and increase production.

Another object of the invention is to develop a method and apparatuswhich effectively make logic decisions for the operator, thereby cuttingdown on labor requirements and increasing accuracy.

A further object of the invention is the development of a shearingmethod which will minimize the task of operator training and education,and will, by its simplicity of operation, minimize operator error.

Another object of this invention is to provide a piece of equipment thatwill utilize the method of this invention.

More specifically, an object of this invention is to provide a shearhaving components controlled according to the method of this invention.

A specific object of this invention is to provide a shear having meansfor indicating to an operator the orientation of stock feed for the nextcut.

SUMMARY OFTHE INVENTION The method of this invention, considered as awhole, includes two major aspects. First is the development ofarepetitive series of operations. The second is a novel arrangement ofthe parts to be cut on the starting stock.

According to this invention, the orientation of feed of materialalternates in a repetitive sequence. Two perpendicular cuts are made onthe sheet of starting material to produce a parts blank and at least onecutoff. The parts blank is then sheared into parts, and the cutoff (orcutoffs) are sheared in two perpendicular cuts into an additional partsblank, and the sequence repeated until the original sheet is entirelyused up.

To determine the arrangement of the different sized parts on thestarting sheet stock, all of the parts to be produced in a given timeperiod are arranged in continuous order of size,

be sized to achieve the optimum utilization thereof from the partsremaining on the list.

The shear used to practice the method of this invention is in partconventional. It must include gauges for determining the amount ofcutoff which can be rapidly and accurately set for each cut, and anautomatically controlled means for returning certain cutoffs to theoperator for further processing.

In addition, this invention contemplates the provision of a controlstructure for the shear to indicate to an operator the orientation ofstock feed for each cut. In other words, the method and apparatus ofthis invention are sequenced and coordinated with the operator.

DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of a shearaccording to this invention.

FIG. 2 is a top plan view of a shear according to this invention.

FIG. 3 is an illustration of the control panel for the shear.

FIG. 4 is a diagrammatic illustration ofa sheet of stock illustratingthe sequence of cuts according to this invention.

FIG. 5 is a schematic diagram showing an electronic data input andcontrol system for carrying out this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 respectively showin perspective and in top plan view a shear which may be used topractice the method of this invention. The shear has the horizontaltable 10, and the side plates 12 and 14. Vertically reeiprocable betweenthe side plates 12 and 14 is the ram 16 which carries the knife 18. Asis well known in the art, the ram 16 and knife 18 can be reciprocatedvertically by hydraulic cylinders or by a mechanical drive. Theseelements of the shear do not per se form a part of this invention, andhence will not be described in detail.

Referring now to FIG. 2, it will be seen that the shear is shownequipped with a back gauge 20. As is well known in the art, the backgauge is maintained parallel to the knife, and is movable toward andaway therefrom to provide an adjustable stop against which the stockbeing sheared is placed. The back gauge may be provided with the probes22 which insure that the stock being sheared is in proper contact withthe back gauge prior to the shearing step.

The shear is also provided with the squaring arm 24 having the probes 26for insuring squareness of material. The squaring arm may also beprovided with a front gauge 28 which serves as a stop when the cutofflength exceeds the limits of the back gauge settings.

A flip-flop scrap return chute is indicated generally at 29. In oneposition, this chute will return a piece to the operator for reshearing;in its other position, it will discharge a cutoff as scrap.

As indicated earlier, one important aspect of the method of thisinvention is the development of a repetitive sequence of shearingoperations. For convenience in discussing these operations, the phraseshearing by length will be used to refer to a cut which is parallel tothe long dimension of this stock, and the phrase shearing by width" willbe used to refer to a cut which is parallel to the short dimension ofthe material.

This invention contemplates that a sheet ofstarting material is shearedby length and then sheared by width to produce a first parts blank andat least one cutoff. This operation will often be designated hereinafteras the primary sizing operation.

The first parts blank produced as just described will then be sheared bylength and then by width (as necessary) into a plurality of parts.

The cutoff or cutoffs produced by the primary sizing opera tion are thensheared by length and then by width to produce additional parts blanks.This operation will generally be referred to as the secondary sizingoperation. These additional parts blanks are then sheared as necessaryinto partsuntil the entire starting sheet of stock is used up.

The second necessary aspect of the method of this invention resides inthe arrangement of parts to be produced on the starting sheets.According to this invention, all of the required parts are arranged in alist so that the largest part, by area, is first, with the rest of theparts arranged in descending order by area. For present purposes, let usarbitrarily assume that 26 different parts are to be produced,designated by the letters A through Z." The largest part we will assumeis represented by the letter A and the smallest part by the letterGenerally considered, this invention contemplates that the primarysizing operation as described above will yield a parts blank to produceas many as possible of the largest uncut part to be produced, while thesecondary sizing operation will produce a parts blank for a smalleruncut part so as to achieve optimum utilization of the cutoff. It isbelieved that the following example will facilitate an understanding ofthe method of this invention.

1n the practice of this invention, it is possible to utilize a singlestarting sheet size. Taking a single sheet of material, the first stepis to arrange as many of the largest part to be produced as possible onthe sheet. The arrangement is diagrammatically illustrated in FIG. 4,wherein a sheet of starting material is indicated at 40. it will beobserved that the upper left-hand portion of FIG. 4 is divided intoequal sized rectangles representing part A, the largest part to beproduced.

The first cutoff is made by setting the back gauge to the distance 42,and shearing the sheet by length along the line 44. it will be observedthat this first cut produces a portion of a width 46 equal to at leastone multiple ofa part width, and a first cutoff indicated at 48. If thiscutoff is less than a predetermined width, the flip-flop chute willreject it as scrap. Otherwise, it will be returned to the operator viathe return chute for further processing as hereinafter set forth.

The portion containing the 10 A parts is then sheared by width along theline 50 to produce a parts blank having a length 52 equal to at'leastone multiple of the desired part length, and a second cutoff indicatedat 54.

As already indicated, this operation of producing a first parts blankfrom a full sized sheet of material is referred to as the primary sizingoperation. This primary sizing operation will generate two cutoffs solong as the part length and part width are not even multiples of thesheet length and width respectively.

The parts blank created by the first two shear cuts is next sheared intoparts. The back gauge is set at the distance 56, and the parts blank issheared by length alongthe lines 58, and 60 to produce three rows ofparts. Finally, the back gauge is set at the distance 62, and the rowsare sheared by width to produce the 10 required parts. ln the exampleshown in H0. 4 it will be observed that a third cutoff is created,indicated at 64.

A review of the procedure followed to produce this first set of partsreveals a definite repetitive operation. That is, the

starting stock is first sheared by length, then by width to produce aparts blank and two cutoffs. The parts blank is then sheared by lengthto produce the number of rows needed, and finally by width to producethe number of parts required.

At this point in the operation, there are now three cutoffs, 48, 54, and64. lt is now necessary to find the best parts to be produced from thesecutoffs. As previously indicated, this will be referred to as thesecondary sizing operation.

This secondary sizing operation is substantially the same as the primarysizing operation, except that rather than use the largest part to beproduced, the list of uncut parts will be checked, and considering bothsize and quantity of these uncut parts, a smaller part will be selectedand arranged on the cutoff to effect optimum utilization thereof andminimum scrap. (The control panel described hereinafter will indicate tothe operator which cutoff is to be used.) The procedure for the shearingoperation of these cutoffs in the secondary sizing operation is exactlythe same as that used for the primary sizing operation, that is, shearby length and shear by width to produce a parts blank; shear the partsblank by length into rows, and shear the rows by width into individualparts.

it will be apparent from the foregoing discussion that according to thismethod, a given sheet of stock is processed completely beforeusinganother sheet of stock.

After the first sheet has been completed, a second sheet of stock willbe obtained, and another primary sizing operation will be begun. Thistime, the list will be checked to see of all of the largest parts to beproduced were made. if they were not, as many of these parts as possible(or as necessary) would be arranged on the stock sheet, which is againsheared by length and width to produce a parts blank and two cutoffs, inthe event that all of the largest parts had already been completed inthe first primary sizing operation, the next largest part in the list,part B" would be selected, and as many as possible of this part would bearranged on the starting sheet, and the sheet sheared by length and bywidth to produce a parts blank and two cutoffs. The parts blank issheared by length and by width to produce the required number of partsand perhaps a third cutoff, and then the secondary sizing operation iscarried out, starting with the optimum uncut part on the list.

As already indicated, the parts to be produced have been listed in orderof area. Therefore, it can be assumed that in general the primary sizingoperation on the first selected sheet of stock will yield cutoffs whichare smaller in area than those yielded by any other primary sizingoperation that will be done for thisparticular parts list. Therefore,the secondary sizing operation requires that smaller parts be made fromthese eutoffs. As the next largest parts, B," C," etc. are produced,

the cutoffs from the primary sizing operation become in generalprogressively larger in area. It again follows that progressively largerparts in general can be produced in the secondary sizing operation.Thus, in its simplest aspect, the primary sizing operation according tothis method requires the utilization of parts from the top of the listand progressing downward, while the secondary sizing operation generallystarts near the bottom of the list and continues progressively upward.As the operation continues, the two sizing operations will convergesomewhere near the center of the list.

What this means to the scrap generated is that as larger cutoffs areproduced, there are larger parts available to size to them. therebygenerating the least amount of scrap for the shearing ofa particularparts list.

The method as described above can be practiced by the operator manuallysetting the gauges and return chute for each shear cut. However, thestructured, repetitive nature of the process as described facilitatesautomatic setting of the shear components in response to suitable dataprocessing equipment. Such equipment does not form a part of thisinvention per se, and need not be described in detail in thisapplication.

FIG. 5 is a schematic diagram showing an electronic data input andcontrol system for carrying out this invention. Bulk data informationwill be supplied at 70. It will of course be understood that the datainformation may be supplied via punched cards, punched tape, magnetictape, or even a direct connection to the output of a suitable computer.

As will be apparent from perusing the remainder of this figure, theinput information must include data for setting the position ofthe scrapreturn chute 29, for operating the opera tor command display to bedescribed later, for setting the front and back guages of the shear tothe proper position, for activating the probes on the squaring arm andback gauge in accordance with the size of the material being sheared,and for activating the shear control.

This input data is first interpolated and scanned in the proper sequenceat 72, so that the various commands will be given in the proper order.

The information is then directed to the command center 74, which will ineffect convert the input information into appropriate machine settings.For example, information from the command center 74 can be utilized toset the scrap return chute as indicated at 76. At substantially the sametime, the command center 74 will send appropriate directions to theoperator command display indicated at 78, to be described presently.

The command center will also via conventional circuitry energize theback gauge control 80 to move the back gauge to a predeterminedposition. The encoder 82 is basically an independent device formeasuring the position of the back gauge, and signals from the encoder82 and back gauge 80 are compared in the comparator 84 to double checkon accuracy.

The setting of the front gauge must of course be coordinated with theoperation of the back gauge. That is, for shear cuts less than a certainlength, the front gauge will be inactive. However, for cuts over thispredetermined distance, the back gauge will be inactive and the frontgauge will control cutoff width. In this case, appropriate signals willbe sent from the command center 74 to the front gauge control 86. Again,the encoder 88 will determine the position of the front gauge, and itsdata will be compared with the command sent to the gauge control 86 inthe comparator 90.

As is well known in the art, the back gauge and squaring arm of theshear are generally provided with a plurality of probes, indicatedschematically in FIG. 2 at 22 and 26 respectively. Under normaloperating conditions, only two of the back gauge probes 22 will be inoperation for any given shear cut, depending of course up on thedimensions of the sheet being sheared. Similarly, the probes 26 on thesquaring arm 24 will be in operation only when required. Suitable inputdata will be provided so that the command center 74 will, via the backprobe control 92 and squaring front probe control 94 activate the properprobes.

Finally, the command center 74 will set the shear control 96 so that thecut can be made after all appropriate settings have been made. It willof course be understood that the shear can be operated manually,semiautomatically, or fully automatically.

When the commands to all of the foregoing components have been fullyexecuted, appropriate signals will be sent from each unit to the programadvance control 98, which will in turn signal the new data command unit100 and the scanning control 72 for receipt ofthe next block of datainformation.

Whether gauge and other machine settings are made automatically ormanually, the stockto be sheared must still be fed manually. Therefore,in order to make this process operational from the practical standpoint,it is necessary to coordinate stock selection and orientation of feed bythe operator with the method of this invention. One exemplary controlstructure for effecting this coordination is shown in FIG. 3. (Thecontrol structure is shown generally in FIGS. 1 and 2 at 110.)

The control structure 110 includes a panel 112 having a plurality ofapertures, behind which are disposed conventional means for displayingsuitable indicia. For example, the aperture 114 in FIG. 3 is designatedsheet length. Behind the aperture will be means for displaying thelength of the starting material in six digits. In the example shown, thesheet length is l20.000 inches.

Similarly, the aperture 116 is designated sheet width," and through theaperture a five-digit display is visible indicating an exemplary sheetwidth of 48,000 inches.

The apertures 118 and 120 respectively are designated parts lenght andparts width." The dimensions of the exemplary part to be cut are 39.625inches by 28.750 inches.

Assuming that the starting stock has an original size of 120 inches by48 inches, it will be recalled that the primary sizing operation callsfor the arranging of as many of a part as possible on the startingsheet. It will be observed that three piece. of the exemplary part notedabove can be cut from the starting sheet of this size, and a three-digitdisplay for indicating the number of parts to be produced from a givensheet are visible behind the aperture 122. Similarly, a two-digitdisplay is visible behind the aperture 124 which may serve to indicatethe position of the scrap return chute.

The apertures 126 and 128 are designated respectively gauge length" andgauge width. Five-digit displays are visible behind both of theapertures, each of which is designed to register the back gauge settingof the machine. These displays are arranged through conventional wiringand control so that only one of them will be visible for any given cut,so that the operator, by determining which display is visible, is ableto im mediately determine the orientation of stock feed.

For example, according to the method of this invention a sheet of stockis first sheared by length. Using the figures set out above, threepieces, each having a width of 28,750 inches are to be cut from a sheethaving a starting width of 48,000 inches, making a cutoff of l9.250inches. For this initial cut, only the display behind the gauge lengthaperture 126 will be visible, so that the operator knows that the sheetmust be fed with its long edge parallel to the knife.

Still using the exemplary figures above, the sheet must be sheared bywidth. Three pieces, each having a length of 39.625 inches are to be cutfrom a starting sheet having a length of I20.000 inches. The totallength of the parts blank will therefore be ll8.875 inches, and thecutoffmust be l.l25 inches. The orientation of feed is indicated to theoperator by the fact that the gauge width display 128 is visible, whilethe gauge length display 126 will not be visible.

The parts blank created by the foregoing primary sizing operation isthen sheared by length into a number of parts rows, and the rows aresheared by width into the individual arts. It is of course possible touse the gauge length display 126 and the gauge width display 128 notedabove in order to indicate the orientation of stock feed for these cuts,but in some cases, a further refinement may be desirable. That is, it isalso contemplated by this invention that when the gauge setting for agiven cut corresponds to either part length or part width, only theappropriate display in aperture 118 or respectively will be visible. Inother words, during the primary and secondary sizing operations whereingauge settings are more than one multiple ofpart length or part width,the gauge length display 126 or gauge width display 128 will indicatethe orientation of stock feed to the operator. On the other hand, whenthe gauge setting corresponds to either part length or part width,-onlycorresponding part length display 118 or part width display 120 will bevisible, thereby indicating the orien tation of feed for these cuts.

It will be recalled that the primary sizing operation yields at leastone cutoff, and referring back to the earlier examph may produce as manyas three cutoffs, upon which the secondary sizing operation is carriedout. At the completion of the primary sizing operation, and theproduction of individual parts from the parts blank, the displays behindapertures 114 and 116 will change, indicating a new sheet length andsheet width corresponding to one of the cutoffs produced in the primarysizing operation. This will give a clear indication to an operator ofwhich of the various returned cutoffs is to be utilized for thesecondary sizing operation. The operation of the remainder of thedisplays will correspond to the exemplary operation described above.

The aperture 130 in FIG. 3 is designated front gauge." Visible behindthis aperture is a six-digit display indicating the position of thefront gauge. As explained earlier, the front gauge is utilized todetermine length of cutoff beyond the range of the back gaugesettings.

It will of course be understood that the control panel may be providedwith various other indicators to display such additional information asmay be desirable for the operator.

It is believed that the foregoing constitutes a full and completedisclosure of this invention. Numerous modifications may be made withoutdeparting from the scope and spirit thereof. For example, the processcan be employed where several different sized sheets of material areavailable for each primary sizing operation. Similarly, it will beapparent that automatic stock feeding equipment can be employed withsuch a system to achieve further labor economies. While the inventionhas been described in terms of an exemplary embodiment, no limitationsare intended except as specifically set forth in the claims whichfollow.

We claim:

1. A method of shearing from stock a plurality of different sized partsin an array of parts according to magnitude of area comprising the stepsof: I

a. shearing said sheet by length and width to produce a part blank of alength and width equal to at least one multiple of the length and widthof substantially the largest part in said array of parts and producing alength cutoff and a width cutoff;

b. shearing said part blank to produce at least one multiple of saidsubstantially largest part;

c. selecting by a computer means from the smaller parts in the array ofparts, the part which can be sheared from the length cutoff withsubstantially least scrap and shearing the length cutoff to produce atleast one multiple of the selected part;

d. selecting by computer means from the smaller parts in the array ofparts. the part which can be sheared from the width cutoff withsubstantially the least scrap and shearing at least one multiple of theselected part.

2. The method of claim 1 including the additional step of selecting asecond sheet of stock, shearing as many as possible of the saidsubstantially largest of said parts to be cut, said shearing stepproducing a length cutoff and a width cutoff, selecting by computermeans from the smaller of the parts to be cut the part which can besheared from the length cutoff with substantially the least scrap andshearing the length cu toff to produce at least one multiple of theselected part, and selecting by computer means from the smaller of saidparts to be cut, the part which can be sheared from the width cutoff 0with substantially the least scrap and shearing the width cutoff toproduce at least one multiple of the selected part.

3. A method of shearing an elongated sheet of stock to produce aplurality of different sized parts comprising the steps of:

a. shearing said sheet lengthwise to produce a portion with a widthequal to at least one multiple ofa part width, and a first cutoff;

b. then shearing said portion by width to produce a part blank with alength equal to at least one multiple of said part length and a secondcutoff;

c. shearing said part blank by length and then by width to produce saidpart;

d. thereafter shearing said first cutoff by length and then by width toproduce a second part blank for a second part; and

4. A method of shearing an elongated sheet of stock to produce aplurality of different sized parts comprising the steps of:

a. shearing said sheet lengthwise to produce a portion with a widthequal to at least one multiple ofa part width, and a first cutoff;

b. then shearing said portion by width to produce a part blank with alength equal to at least one multiple of said part length and a secondcutoff;

c. shearing said part blank by length and then by width to produce saidpart;

d. thereafter shearing said first cutoff by length and then by width toproduce a second part blank for a second part;

e. shearing said second part blank by length and then by width toproduce said second part; and

f. shearing said second cutoff by length and then by width to produce athird part blank for a third part 5. A method of shearing a plurality ofdifferent sized parts from sheetstock comprisin the steps of a. seiectmgthe substantia ly largest part to be cut and shearing said sheet stockby length and then by width to produce a parts blank having a length anda width equal respectively to at least one multiple of said part lengthand width, and a first and second cutoff;

b. selecting a substantially smaller part to be cut which can be shearedfrom said first cutoff with substantially the op timum utilization ofsaid first cutoffand the least scrap;

c. shearing said first cutoff by length and then by width to produce asecond parts blank having a length and a width equal respectively to atleast one multiple of said smaller part length and width; and

d. providing visual display means for indicating to an opera tor theorientation of stock feed for each said shearing cut including theprovision of two indicators each adapted to display sheared dimensions,and displaying only one of said indicators.

6. The method claimed in claim 5 including the step of shearing saidfirst mentioned arts blank by length and then by width to produce atleast one of said largest part to be cut prior to said step of selectingthe smaller part to be cut.

7. The method claimed in claim 5 including the step of shearing saidsecond parts blank by length and then by width to produce at least oneof a smaller part to be cut.

8. In a manufacturing process wherein a plurality of different sizedparts each having a specified quantity requirement are sheared fromstock, the improved method of minimizing scrap comprising the steps of:

at arranging said parts to be cut into substantially consecutive orderas to area;

b. selecting a first sheet of said stock;

c. shearing a parts blank of a size to include at least two of thesubstantially largest of said parts to be cut from said first sheet ofstock, said shearing step producing at least a first cutoff;

d. selecting the smaller uncut part which in any portion of quantityrequired can be cut from said first cutoff with the least unused stock;and

e. shearing as many of said smaller parts as possible from said firstcutoff.

32 5 UNITED STATES PATENT OFFICE CERTIFICATE CF CORRECTION Patent No.3,598 O07 Dated August 10, 197].

Inventor(s) Ronald S. Williams and John J. Erhart It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 7, after line 56, please insert (e) shearing said second cutoffby length and then by width to produce a third part blank for a thirdpart.

Signed and sealed this 25th day of April 197 (SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents

1. A method of shearing from stock a plurality of different sized partsin an array of parts according to magnitude of area comprising the stepsof: a. shearing said sheet by length and width to produce a part blankof a length and width equal to at least one multiple of the length andwidth of substantially the largest part in said array of parts andproducing a length cutoff and a width cutoff; b. shearing said partblank to produce at least one multiple of said substantially largestpart; c. selecting by computer means from the smaller parts in the arrayof parts, the part which can be sheared from the length cutoff withsubstantially least scrap and shearing the length cutoff to produce atleast one multiple of the selected part; d. selecting by computer meansfrom the smaller parts in the array of parts, the part which can besheared from the width cutoff with substantially the least scrap andshearing at least one multiple of the selected part.
 2. The method ofclaim 1 including the additional step of selecting a second sheet ofstock, shearing as many as possible of the said substantially largest ofsaid parts to be cut, said shearing step producing a length cutoff and awidth cutoff, selecting by computer means from the smaller of the partsto be cut the part which can be sheared from the length cutoff withsubstantially the least scrap and shearing the length cutoff to produceaT least one multiple of the selected part, and selecting by computermeans from the smaller of said parts to be cut, the part which can besheared from the width cutoff with substantially the least scrap andshearing the width cutoff to produce at least one multiple of theselected part.
 3. A method of shearing an elongated sheet of stock toproduce a plurality of different sized parts comprising the steps of: a.shearing said sheet lengthwise to produce a portion with a width equalto at least one multiple of a part width, and a first cutoff; b. thenshearing said portion by width to produce a part blank with a lengthequal to at least one multiple of said part length and a second cutoff;c. shearing said part blank by length and then by width to produce saidpart; d. thereafter shearing said first cutoff by length and then bywidth to produce a second part blank for a second part; and e. shearingsaid second cutoff by length and then by width to produce a third partblank for a third part.
 4. A method of shearing an elongated sheet ofstock to produce a plurality of different sized parts comprising thesteps of: a. shearing said sheet lengthwise to produce a portion with awidth equal to at least one multiple of a part width, and a firstcutoff; b. then shearing said portion by width to produce a part blankwith a length equal to at least one multiple of said part length and asecond cutoff; c. shearing said part blank by length and then by widthto produce said part; d. thereafter shearing said first cutoff by lengthand then by width to produce a second part blank for a second part; e.shearing said second part blank by length and then by width to producesaid second part; and f. shearing said second cutoff by length and thenby width to produce a third part blank for a third part.
 5. A method ofshearing a plurality of different sized parts from sheet stockcomprising the steps of: a. selecting the substantially largest part tobe cut and shearing said sheet stock by length and then by width toproduce a parts blank having a length and a width equal respectively toat least one multiple of said part length and width, and a first andsecond cutoff; b. selecting a substantially smaller part to be cut whichcan be sheared from said first cutoff with substantially the optimumutilization of said first cutoff and the least scrap; c. shearing saidfirst cutoff by length and then by width to produce a second parts blankhaving a length and a width equal respectively to at least one multipleof said smaller part length and width; and d. providing visual displaymeans for indicating to an operator the orientation of stock feed foreach said shearing cut including the provision of two indicators eachadapted to display sheared dimensions, and displaying only one of saidindicators.
 6. The method claimed in claim 5 including the step ofshearing said first mentioned parts blank by length and then by width toproduce at least one of said largest part to be cut prior to said stepof selecting the smaller part to be cut.
 7. The method claimed in claim5 including the step of shearing said second parts blank by length andthen by width to produce at least one of a smaller part to be cut.
 8. Ina manufacturing process wherein a plurality of different sized partseach having a specified quantity requirement are sheared from stock, theimproved method of minimizing scrap comprising the steps of: a.arranging said parts to be cut into substantially consecutive order asto area; b. selecting a first sheet of said stock; c. shearing a partsblank of a size to include at least two of the substantially largest ofsaid parts to be cut from said first sheet of stock, said shearing stepproducing at least a first cutoff; d. selecting the smaller uncut partwhich in any portion of quantity required can be cut from said firstcutoff with the least unused stock; and e. shearing as mAny of saidsmaller parts as possible from said first cutoff. cutoff.